A cost-effective Software Development and Validation environment and approach for LEON based satellite & payload subsystems

This paper describes a configurable Software Development and Validation Facility (SDVF), designed to support the lifecycle of spacecraft equipment containing on board software (OBSW) in our case LEON-based units with a cost effective approach. The environment fulfils three main purposes: 1. Software Development and Verification Facility (SDVF) for OBSW 2. Simulation for performance and design feasibility assessment 3. Special Check-Out Equipment (SCOE) for hardware integration and testing With a modular design, it can be modified into different configurations, from a full-virtual environment containing a processor emulator and a set of simulation models, to a processor in the loop (PIL) or complete hardware in the loop (HIL) configuration. As the use case is not limited to the SDVF only, we called the environment "EGSE-Lite". The key design characteristics of the system are: 1) Easy configurability to use virtual models or real hardware versions of system components or a mix of them: A central "Packet Switch" interconnects the modules and allows easy switch from one configuration to another via a configuration file. This is possible as the modules, either virtual or hardware via their interface driver, shares a common interface protocol. 2) Simple coupling of interfaces among the equipment modules, based on TCP/IP sockets. The solution allows distributing the modules on different host machines if needed. 3) Use of ESA's SCOS-2000 software as Central Check out System (CCS): The integration of SCOS allows easy system level testing of the software, to edit and send commands, verify telemetry results on displays, archive telemetry for offline analysis and enable automated regression testing. It also enforces compatibility of the equipment under development with the final system EGSE or mission control system, if based on SCOS2000. 4) Packet sniffing and recording capability at different levels with capability to inject corrupted packets for robustness validation of the system. 5) Use of Eclipse and LEON Integrated Development Environment (LIDE) available from Gaisler Research, providing a development environment with GDB interface for debugging. 6) Possibility to use either a virtual LEON emulator, such as Gaisler Research TSIM, or a hybrid hardware/software emulator, or the final LEON processor board. Use of COTS I/O cards such as PCI-SpaceWire interface card and other standard interfaces to connect to the hardware equipment. The facility has been successfully deployed to CESR, an institute in France for astrophysics and payload development and integration, providing emulation of a LEON3 processor, high fidelity models for X-ray detectors and a NAND based fault tolerant mass memory unit, each replaceable with its hardware counterpart (the processor board was based on Aeroflex LEON3 UT699). The environment is currently being integrated with a LEON2 hybrid hardware/software emulator developed by ASTRIUM under ESA contract (LeonSvf): The objective is to perform a characterization study of the emulator card using computational intensive flight representative software developed for CESR The EGSE-Lite takes full advantage from COTS products (such as Gaisler TSIM), and ESA software products (such as SCOS 2000) to provide a light weight, scalable and cost-efficient solution, for integration and validation of satellite subsystems and payload equipment containing embedded software.